Reuters: Atmospheric levels of the main greenhouse gas are hitting new highs, with no sign yet that the world economic downturn is curbing industrial emissions, a leading scientist said on Thursday. “The rise is in line with the long-term trend,” Kim Holmen, research director at the Norwegian Polar Institute, said of the measurements taken by a Stockholm University project on the Arctic archipelago of Svalbard off north Norway. Levels of carbon dioxide, the main greenhouse gas from …